用c语言实现两个一元多项式相加

在C语言中，你可以通过结构体来表示一元多项式，并设计函数来实现两个多项式的相加。下面是一个简单的例子：

#include <stdio.h>
#include <stdlib.h>

// 定义多项式结构体
typedef struct {
    int coefficient; // 系数
    int degree;       // 次数
} Polynomial;

// 动态分配空间存储多项式
Polynomial* create_polynomial(int degree) {
    Polynomial* poly = (Polynomial*)malloc(sizeof(Polynomial));
    poly->coefficient = 0;
    poly->degree = degree;
    return poly;
}

// 相加两个多项式
void add_poly(Polynomial* poly1, Polynomial* poly2, Polynomial** result) {
    *result = create_polynomial(max(poly1->degree, poly2->degree)); // 创建结果多项式的空间

    for (int i = 0; i <= (*result)->degree; ++i) {
        if (i <= poly1->degree && poly1->coefficient != 0)
            (*result)->coefficient += poly1->coefficient;
        if (i <= poly2->degree && poly2->coefficient != 0)
            (*result)->coefficient += poly2->coefficient;
    }
}

// 打印多项式
void print_poly(Polynomial* poly) {
    printf("P(x) = %d * x^%d + ", poly->coefficient, poly->degree);
    if (poly->degree > 0)
        print_poly(create_polynomial(--poly->degree));
    else
        printf("0\n");
}

int main() {
    Polynomial* poly1 = create_polynomial(2);
    Polynomial* poly2 = create_polynomial(3);

    poly1->coefficient = 4;
    poly1->degree = 2;
    poly2->coefficient = -2;
    poly2->degree = 3;

    Polynomial* sum_poly = NULL;
    add_poly(poly1, poly2, &sum_poly);

    printf("First polynomial: P1(x) = ");
    print_poly(poly1);
    printf("Second polynomial: P2(x) = ");
    print_poly(poly2);
    printf("Sum: P3(x) = ");
    print_poly(sum_poly);

    free(sum_poly); // 释放内存
    free(poly1);
    free(poly2);

    return 0;
}

在这个程序中，我们首先创建了`create_polynomial`函数用于动态分配多项式的存储空间，然后是`add_poly`函数实现了两个多项式的相加，最后有`print_poly`函数用来展示结果。在`main`函数中，我们实例化了两个多项式并进行了相加操作。